This invention relates to a process for producing L-lysine by fermentation, and more particularly to such a process wherein a bacterium belonging to the genus Nocardia is aerobically cultivated in a culture medium, and L-lysine formed in the culture medium is recovered therefrom.
In the prior art, there are many processes for the production of L-lysine by fermentation utilizing bacteria of the genus Nocardia. For example, one such method uses an olefin as a carbon source (U.S. Pat. No. 3,440,141). Another such method uses ethyl alcohol (U.S. Pat. No. 3,595,751). A further example of such method uses a nutrient requiring strain in n-paraffin as a carbon source (U.S. Pat. No. 3,839,151). Also, another such method uses a strain resulting from imparting analog resistance to a nutrient requiring strain (British Patent 1,304,067). Each of these prior methods has its own advantages and disadvantages: most, however, do not produce large quantities of L-lysine. Accordingly, there is considerable room for improvement and substantial industrial effort has been and is being expended to improve the yields, as well as to reduce the cost.